High speed launching device



y 1957 R. N. LAHDE 2,792,755

HIGH SPEED LAUNCHING DEVICE Filed Oct. 31, 1952 2 Sheets-Sheet 1 TT T HUN ."l

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' ATTORIVEYS May 21, 1957 R. N. LAHDE HIGH SPEED LAUNCHING DEVICE Filed Oct. 31, 1952 2 Sheets-Sheet 2 Fig.5

INVENTOR. REiNHARD N. LAHDE A T TOBNE 3 5" HIGH SPEED LAUNCHING DEVICE Reinhard N. Lahde, Camarilio, Calif assignor to the United States of America as represented by the Secretary of the Navy Application October 31, 1952, Serial No. 318,146

4 Ciaims. (CI. 89-15) (Granted under Title 35, U. S. (lode (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

The present invention relates to a high speed launching device and more particularly to a high speed launching device utilizing a piston operating within a slotted cylindrical member and a sealing strip which is adapted to seal the slot in the cylinder.

Although the present invention is adapted to launch various objects into space, it is particularly adapted for use in the launching of high speed missiles wherein it is desirable to obtain launching speeds in excess of 500 ft. per second.

Launching devices utilizing a piston operating within a slotted cylindrical member and a sealing strip are well known. Such a launching device is shown for example in United States Patent No. 2,485,601.

In launching devices previously used, the sealing strip extending from the piston to the open end of the cylinder has been supported by means of hangers passing through the slot in the cylinder and by applying tension to the end of the strip by means of a pneumatic jack. In such devices, the sealing strip extends through a passage in the piston whereby as the piston moves longitudinally within the cylinder the sealing strip is forced into sealing relation with the slot extending behind the piston. It is evident that the pressure developed behind the piston by the source of propulsion such as expanding gases will maintain the strip in sealing position relative to that portion of the slot which extends from the rear of the piston to the closed end of the cylinder.

Prior art launching devices of the above type have proved satisfactory in obtaining launching speeds up to 500 ft. per second; however, when it is attempted to drive the piston and an attached missile at speeds greater than 500 ft. per second, the strip tends to buckle at the mouth of the passage in the piston, thereby causing the strip to jam within the passage and consequently to be often broken. Such buckling is caused by the fact that since the sealing strip is not firmly supported throughout its iength, waves are produced in the strip forwardly of the piston as the piston moves within the cylinder. It is apparent that if the sealing strip breaks, the propulsive energy behind the piston may escape through the slot in the cylinder and propulsive force may no longer be effectively applied to the piston.

The present invention utilizes a novel construction whereby a means is provided which furnishes a firm support for the sealing strip forwardly of the piston during launching. Therefore, substantially no waves are produced in the sealing strip, and as a result, buckling and breaking of the strip are prevented. Consequently, much higher launching speeds may be obtained with the present invention than have been possible with launching devices previously used.

.An object of the present invention is the provision of 2,792,755 Patented May 21, 1957 a new and novel launching device in which high launching speeds are obtainable.

Another object is to provide a launching device utilizing a sealing strip wherein buckling and breaking of the strip are prevented at high launching speeds.

A further object of the invention is the provision of a launching device which is simple in construction, yet sturdy and reliable in operation.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

Fig. 1 shows a side view of the launching device with a missile to be launched mounted thereon,

Fig. 2 illustrates a longitudinal section of the launching device,

Fig. 3 is an end view of the device of Fig. 1,

Fig. 4 shows a section of the device taken on the line 44 of Fig. 2 looking in the direction of the arrows.

Fig. 5 illustrates a modification of the device, and

Fig. 6 is a perspective view of the piston shown in Fig. 5.

Referring now to the drawings wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in Fig. 1 an operating cylinder or barrel member 10 supported by a plurality of standards 11 which are adapted to rest on suitable foundations fixed in the ground. An elongated deck or ramp 12 is also supported by the standards 11 such that the ramp and the cylinder are fixed in parallel relationship closely adjacent to one another. The standards 11 also serve as a lateral support for the wall of the operating cylinder 10 as may be more clearly seen in Fig. 3, thereby strengthening the cylinder to enable it to withstand the high pressures developed within the cylinder during launching.

As shown in Figs. 2 and 3, cylinder 10 and ramp 12 have longitudinally extending elongated slots 13 and 14 respectively formed therein, said slots being aligned with one another and extending throughout the length of the cylinder and ramp, whereby communication may be effected between the piston within the cylinder and the missile supported on the ramp.

Referring again to Fig. 1, a missile 15 is mounted upon a suitable sled 16 which is adapted to travel along the ramp during launching. A pneumatic jack indicated generally by numeral 17 is mounted at the front end of the device and is adapted to apply tension to the end of a sealing means as will be hereinafter more fully described.

In Fig. 2 it may be seen that the cylinder 10 is closed at one end by a removable cap 20 and is closed at its opposite end by a close-fitting plug 21. The piston 22 which fits tightly within cylinder 10 has an arcuately shaped passage 24 formed therein and a tow fitting 23 is secured thereto, said fitting having a width slightly less than slots 13 and 14 and passing therethrough. The tow fitting may be formed integrally with the piston if desired, and is adapted to be suitably secured either directly to the missile or to a sled upon which the missile is mounted.

A ribbon-like sealing strip 25 is suitably secured at one end thereof as by means of a bolt 26 to the interior of the cylinder 10 adjacent to member 20 and extendsthrough the passage 24 in piston 22 and thence through a close-fitting slot 27 in plug 21. Strip 25 is secured at its opposite end as by means of a shear pin 28 to an arm 29 which is pivoted at 30 to arm 33 which is secured to piston 34 tightly fitting slidably within cylinder 35. Conventional means is provided for applying fluid pressure to cylinder 35 whereby upon the introduction of fluid pressure within the cylinder 35 to the right of piston 34, the piston will be urged to the left causing arms 29 and 33 to move to the left thereby applying tension to the sealing strip.

In accordance with the present invention, a means is provided for firmly supporting the sealing strip forwardly of the piston. As shown in Fig. 2, a suitable orifice 36 is formed in the wall of the cylinder 10 whereby a compressible fluid such as air under pressure may be intro duced into cylinder 10 forwardly of the piston, and this fluid pressure will force strip 25 into sealing position such that a closed chamber 38 is formed forwardly of the piston. Since the sealing strip is pressed firmly against the inner periphery of the cylinder 10, the strip is supported throughout that portion of its length within the cylinder which extends forwardly of the piston.

As the sealing strip is supported against the cylinder wall, it becomes necessary to provide a means to quickly and efficiently divert the strip into the passage in the piston as the piston moves within the cylinder. Accrdingly, the passage 24 is arcuately shaped, extending from the top of the piston at its front end 40 and sloping slightly downward to the center of the piston and then upwardly to the top of the piston at its rear end 41, so that the displacement of the strip may beas gradual as possible. The piston has formed thereon a beveled edge 37 which is forced between the cylinder wall and the sealing strip as the piston moves within the cylinder, thereby serving to displace the strip away from the cylinder wall and to guide it into the passage in the piston. The upwardly directed rearward portion of the passage forces the strip back into sealing position relative to the cylinder and the pressure produced by the propulsive energy in chamber 39 behind the piston will maintain the strip in sealing position rearwardly of the piston as shown in Fig. 4.

The propulsive energy to drive the piston within the cylinder may be produced by conventional sources of energy such as fluid pressure, smokeless powder or the like.

There is shown in Fig. a modification of the device wherein a modified piston is utilized which is fabricated of a number of separate members which are suitably secured in position. The piston consists of a circular head portion 45 which fits tightly within the cylinder and a hollow cylindrical tube 46 is suitably secured concentrically to head piston 45. Guide members 47 and 48 and a tow fitting 49 are securedas by welding to member 46, and opposite ends of the tow fitting abut against adjacent ends of the guide members. The guide members and tow fitting have passages formed therein .such that when in assembled position as shown in Fig. 5,

similarly to the device as shown in Fig. 2 and in accordance with the principles of the invention.

Referring to Fig. 6, tube 46 is supported within the cylinder at its forward end by a plurality of shoes 51, shown as three in number, which are connected to member 46 by means of support members 52. Tube 46 is supported within the cylinder at its rear end by means of head portion 45 and a shoe 53 connected to member 46 by means of support member 54. The shoes are adapted to slide along the inner wall of the cylinder and the bearing surfaces thereof are preferably formed of antifriction material so as not to impede the travel of the piston. It is evident that the shoes may be of any suitable configuration and dimensions and that any desired number may be employed.

Although it is not necessary to apply tension to the end of the sealing strip of the present invention since the scaling strip is' firmly supported forwardly of the piston, such tension serves to originally position the sealing strip closely adjacent to slot 14 forwardly of the piston whereby the fluid pressure introduced through orifice 36,, is only;

required to displace the strip a small distance to force it into contact with the inner wall of the cylinder and to seal the slot in the cylinder in front of the piston. Such tensioning also assists in maintaining the strip flat against the inner wall of the cylinder should the strip tend to buckle during launching.

The operation of the invention device as shown in Fig. 2 is as follows: The piston 22 is initially positioned in cylinder 10 adjacent to cap 20, and a missile 15 is mounted upon a sled 16, which is supported on the deck 12 and is suitably secured to the tow fitting 23. The pneumatic jack is actuated so as to apply tension to the sealing strip and fluid at approximately two p. s. i. pressure is introduced into cylinder 10 through orifice 36 such that the sealing strip is forced into sealing position and is thereby firmly supported forwardly of the piston. iropulsive energy is then suitably introduced into cylinder It) to the right of piston 22 whereby the piston is forced to move to the left within the cylinder. As the piston moves within the cylinder 16, the edge 37 forces the strip away from the inner wall of the cylinder and guides it into the passage 24. The strip 25 is displaced laterally away from the inner wall of the cylinder and then forced into sealing position at the rearward portion of the piston dueto the arcuate shape of passage 24, thereby forming a closed chamber behind the piston. As pointed out previously, propulsive energy of the device maintains the strip in sealing position behind the piston. Piston 22 travels between and feet during the launching stroke, and when end 4 3 of the piston has traveled approximately 75 feet, or at about the midpoint of the launching stroke, the pressure in front of the piston has built up sufficiently such that plug 21 is blown out of the cylinder, shearing off pin 28, and rotating arm 29 into the dotted line position shown in Fig. 2. The piston continues to travel along within the cylinder until it passes through the open end of the cylinder whereupon it drops to the ground and the missile becomes airborne. It should be noted that although the plug is blown out of the cylinder about halfway through the launching stroke thereby releasing the fluid pressure which was introduced through orifice 36, the face pressure built up by end 40 of the piston is greater than the pressure initially acting to hold the strip in place and will tend to maintain the strip in engagement with the cylinder. Furthermore, depending on the launching speed, only a period of approximately .05 to .15 second elapses between the time the plug blows out of the cylinder and the time the piston reaches the open end of the cylinder, and since the sealing strip has a relatively small mass, the force of gravity does not materially affect the position of the strip in such a short period of time. It is also an advantage to have the relatively slow moving plug strike arm 29 rather than the fast moving piston thereby preventing possible distortion of and damage to the arm. Since the fluid pressure introduced through orifice 36 positions the sealing strip in engagement with the inner wall of the cylinder, and the strip is maintainedin engagement therewith during substantially the entire launching procedure, the formation of waves in the strip is prevented. Furthermore, edge 37 and passage 24 are so designed as to produce as smooth and gradual a displacement of the Strip as possible, whereby any tendency of the strip to double up or jam Within the passage is eliminated. Consequently, buckling and subsequent breaking of the strip is prevented, enabling the device to be operated at speeds greater than 500 feet per second. The operation of the device shown in Figs. 5 and 6 is similar to that of the device shown in Fig. 2.

It should be understood that although fluid pressure is considered to be preferable in supporting the strip in front of the piston, that other means may also be provided for such purpose. For example, a suitable adhesive substance such as glue, cement or the like may be used to secure the strip tothe cylinder. Further, the strip may be formed at least partially of a magnetized material such as cobalt steel or the like in which case the strip would be tightly held against the interior of the cylinder by magnetic attraction. In the above modifications, the strip is firmly supported in front of the piston with or without the aid of tensioning means and the device functions in substantially the same manner as when fluid pressure is utilized.

It is apparent from the foregoing that a launching device is provided in which high launching speeds are obtainable without breaking the sealing strip utilized therein, and that the device is simple in construction, yet sturdy and reliable in operation.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

I claim:

1. A launching mechanism which comprises an elon gated hollow cylindrical member having a longitudinally extending slot formed therein, a piston in said hollow member, a tow fitting connected to said piston and extending through said slot, means for sealing said slot and means acting substantially radially the member prior to and during launching movement of the piston for maintaining said foregoing means in sealing engagement relative to substantially the entire length of said slot forwardly of said piston.

2. A launching mechanism which comprises a barrel member closed at both ends and having a longitudinally extending slot formed therein, a piston in said barrel member, a tow fitting connected to said piston and extending through said slot, means for sealing said slot, said piston having means closely adjacent said wall for receiving said sealing means, and gaseous pressure means introduced in said barrel member prior to and during launching movement of the piston for maintaining said sealing means in engagement with that portion of the inner periphery of said barrel member directly in front of said piston during launching, and in sealing relation with said slot throughout substantially the entire length of said slot.

3. A launching mechanism which comprises a slotted tube closed at both ends, a piston slidably mounted within said tube and adapted to be initially positioned adjacent one of said closed ends, towing means on said piston passing through said slot and adapted for connection with a missile, means for sealing the slot in the tube forward of and behind the piston so as to form closed chambers on each side thereof, and gaseous pressure means introduced in said tube prior to and during launching movement of the piston adapted to support said sealing means firmly against the inner periphery of said tube such that substantially the entire length of the tube slot forwardly of said piston is sealed, and means for releasing the pressure build-up before the piston at a predetermined time in the launching movement.

4. In a missile launcher, a ramp having a longitudinal slot formed therein, a rigidly supported cylinder located adjacent to said ramp and being closed at forward and after ends, said cylinder having a slot aligned with the slot in said ramp, the forward end of the cylinder being an ejectable plug, a piston slidably mounted in said cylinder, a tow fitting secured to said piston and passing through said aligned slots, means for sealing the slot in said cylinder and means for maintaining said sealing means in engagement with the inner periphery of said cylinder on both sides of said piston throughout substantially the entire length of said cylinder on both sides of the piston, thereby forming a closed chamber on both sides of said piston, said means for maintaining the sealing means in the forward chamber being a low pressure gas introduced in said cylinder prior to and during launching movement of the piston, said sealing means extending through an arcuate passage formed in a portion of said piston, said passage extending from the top of the piston at its front end downwardly to the center of the piston and then upwardly to the top of the piston at its other end whereby as said piston moves longitudinally in said cylinder, said sealing means is successively forced out of and back into engagement with the inner periphery of said cylinder.

References Cited in the file of this patent UNITED STATES PATENTS 2,200,427 Merz May 14, 1940 2,485,601 Hickman Oct. 25, 1949 2,497,916 Starnbaugh Feb. 21, 1950 FOREIGN PATENTS 707,679 Germany June 30, 1941 

